Biomedical subjects
Publications and source records attributed to M Reiser.
The degradation of insulin and glucagon was investigated in rat brain, kidney, and liver during postnatal ontogenesis. It was found that a maximal activity around 13 d is unique for CNS and differs remarkably from time-course in liver and kidney. It is concluded that this result supports the hypothesis of a growth promoting role of insulin in developing rat brain.
The value of MR tomography for examining vertebral infiltration by malignant disease and the use of various techniques was examined retrospectively in a material of 68 examinations in 62 patients suffering from metastases, plasmacytomas, primary vertebral tumours and vertebral infiltration from extra-osseous tumours. It was shown that the method is superior to all other imaging methods for demonstrating changes in the bone marrow. The extent of the disease and involvement of neighbouring structures is shown more completely in cases where the disease extends beyond the vertebrae. Improved soft tissue contrast and the availability of various planes are definite advantages, as compared with CT. Tissue diagnosis, however, is not improved by MRT.
The experience with magnetic resonance imaging (MRI) of 37 patients with peripheral soft tissue tumours and tumour-like lesions is reported. MRI proved to be a highly sensitive method in detecting soft tissue tumours. The main advantages of MRI compared to CT were the high contrast resolution of MRI and the multiplanar display. The anatomic setting of the soft parts tumour could be defined in most cases as either intracompartmental or extracompartmental. The relationship to the major neurovascular bundles and bone could be assessed accurately. Tumour-induced subtle periosteal reactions and cortical erosions are better defined with CT and plain film, especially. An imaging technique using small excitation angles, echoes produced by gradient inversion and extremely fast repetition times ("Fast Field Echo Imaging") is capable of producing MR images in only a few seconds acquisition time. Preliminary experience shows that soft tissue tumours can be evaluated with this rapid pulse sequence.
Magnetic resonance tomography (MR) was used to examine the femoral heads of 20 normals and of 56 patients with diseases of the femoral head, including Perthe's disease (four cases), adult necrosis of the femoral head (39 cases) and pain of unknown cause (13 cases). Femoral head necrosis and Perthe's disease regularly produce reduced signal intensity. The localisation of the areas of necrosis can be determined accurately in the coronary and sagittal plane. In 11 femoral heads, necrosis could be demonstrated unequivocally by MR in the presence of normal radiographic findings. Follow-up of nine patients with negative MR findings and indefinite symptoms confirmed the absence of necrosis.
In 79 primary bone tumors and tumorlike lesions of the spine radiological criteria are analyzed, which allow to assess the biological nature. Criteria associated with benign lesions, are: regular, trabecular matrix, osteoplastic matrix, exostotic growth, location in the posterior elements, absent soft tissue mass, and bulging of the vertebra. Criteria suggestive of malignancy are: Soft tissue mass, location inside the vertebral body, no alteration of the vertebral shape, compression fracture, and osteolysis. Benign lesions can be diagnosed with a higher degree of reliability than malignant tumors. Diagnostic accuracy increases in lesions exhibiting more than one criterion of the same group.
Amongst 214 patients with degenerative disc disease, MRT showed focal fat deposition in the vertebral marrow close to the end plate in 87 (41%). The appearances and distribution of these zones is described. Recognition of these common changes is important in differential diagnosis between inflammatory and neoplastic processes.
The degree of haemophilic osteoarthropathy was assessed by the Pettersson-score in 219 knees, elbows and ankles of 40 children and adolescents suffering from haemophilia. 55.3% of the joints were unaffected and only 8 joints showed score values greater than 8. Enlargement of epiphyses (36.1%) and irregular subchondral surface (32.9%) were the most frequent observations, while osteoporosis (5.4%) was only rarely observed. Haemophilic osteoarthropathy was most severe in the ankles, while the knees were only moderately affected. Among 11 patients 493 bleedings into 61 joints were observed during a four-year period. If the bleedings recurred, more than 3 bleedings per year always resulted in haemophilic osteoarthropathy.
Occlusion of the inferior vena cava (IVC) can be either congenital or acquired. Tumors at the porta hepatis are the most common cause of acquired occlusion. Various pathways of venous collateralization are described. The development of a transhepatic venous shunt depends on the isolated inflow of the liver veins into the IVC at different levels, with flow reversal in the most inferior hepatic vein. The case of a 46-year-old female patient with an intrahepatic venous shunt is presented. Ultrasound, computed tomography, magnetic resonance imaging and angiography were performed. Their relative diagnostic values are discussed.
Radiographic, clinical and pathologic abnormalities of diffuse idiopathic skeletal hyperostosis (DISH) are presented. Definite criteria must be fulfilled to differentiate DISH from other diseases of the spine, especially intervertebral osteochondrosis and ankylosing spondylitis. A case of massive DISH in the cervical spine causing dysphagia is described.
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MR was performed in 41 patients suffering from benign and malignant bone and soft-tissue tumor before and after intravenous injection of the paramagnetic agent gadolinium-DTPA (Gd-DTPA). Using T1-weighted parameters, the contrast of tumor tissue versus muscle could be increased by Gd-DTPA. Thus, extraosseous extension as well as infiltration of the spinal canal was depicted to better advantage. Inhomogeneities were visualized with higher frequency and improved contrast. In several instances, there was no differentiation between tumor and adjacent edema without application of Gd-DTPA. T2-weighted images without Gd-DTPA exhibited higher contrast as compared to T1-weighted images after Gd-DTPA. The contrast to tumor tissue versus fat and bone marrow respectively was reduced after applying Gd-DTPA. Thus, for the evaluation of bone marrow infiltration, T1-weighted images without Gd-DTPA proved to be indispensable.
The experience with magnetic resonance imaging (MRI) of 81 patients with primary bone tumours and tumour-like lesions is reported. MRI proved to be a sensitive method of detecting primary bone tumours. Intramedullary and extraosseous parts of bone tumours were delineated better than by plain films and computed tomography (CT). Surgical clips and Harrington rods did not appreciably limit the estimation of tumour recurrence. MRI provided definite advantages compared to CT in the surgical staging of bone tumours and tumour-like lesions. MRI was found to be an imaging method with low specificity. Differentiation of tissue components, such as haematoma, fat, necrosis, and cystic areas, led to a specific diagnosis only in rare cases. Plain films and CT were found to be superior to MRI in assessing the biological activity and the differential diagnosis of bone tumours and tumour-like lesions.
Thirty-one patients with abnormalities of the heart and ten controls were examined by ECG-triggered nuclear resonance tomography. All patients had previously been completely investigated. Chamber sizes and mural thickness could be reliably demonstrated and, in addition, it was possible to show areas which could not be easily investigated by echocardiography. Visualisation of the valves was limited, but intra- and para-cardial lesions could be differentiated by a double echo technique. Absence and defects of septa could be shown exactly, as well as accurate demonstration of the relationship of the large vessels to the cardiac chambers.
Changes of the posterior bony and cartilaginous surfaces of the patella as seen on CT arthrograms are described in the case of bipartite patellae, fractures and ossification defects. Contrary to present opinion, cartilaginous lesions are frequently seen on CT arthrograms. This is also true for discreet and partial ossification defects which are not visible on conventional x-rays and are described here for the first time. The aetiology, morphogenesis and clinical examples are discussed.
The results of MR examinations of 31 women with gynaecological diseases are described; all had CT and histological confirmation at operation. The extent and relationship of the lesions were well demonstrated by the three-dimensional sections of MR, in some cases better than on CT. Variations in the signals allowed better differentiation of myomas and ovarian carcinomas from normal tissue. Like CT, MR tomography was not reliable in showing the extent of infiltration into neighbouring structures.
Intravenous urography using Telebrix was performed on 500 patients. Two hundred patients (group I) received no pre-medication; 300 patients (group II) were premedicated with H1 and H2 receptor antagonists. All patients were examined for signs of contrast reactions, blood pressure, pulse rate and plasma histamine levels. These were measured before and three minutes after the administration of the antihistamine substances and/or the contrast medium, and also at the end of the examination. Following the administration of H1 and H2 receptor antagonists, a slight, transient and insignificant rise in plasma histamine could be demonstrated. Both groups showed a significant rise in plasma histamine levels after the injection of the contrast medium. Although the pre-medicated group contained a higher percentage of high risk patients, there were significantly fewer patients with contrast reactions. Pre-medication with H1 and H2 receptor antagonists in high risk patients is therefore advisable.
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